Computer systems encode information onto storage media such as disks. Such storage media contain a fixed number of smaller units known as physical blocks or sectors. Computer systems organize groups of physical blocks into one or more "volumes". Within these volumes, information is stored within discrete units known as "files". As such, each volume, and in turn each file, consumes a discrete number of physical blocks on the disk or other storage medium.
Responsible for this organization of physical blocks into volumes and files is the operating system utilized by a computer and, specifically, the filing system used by the operating system. Each filing system may encode and represent this organization of physical blocks into volumes and files in fundamentally different ways.
IBM PC.TM. and compatible computers use an operating system collectively known as DOS. Versions of DOS are sold by IBM, Microsoft.TM., and Novell.TM.. The behavior of the operating system, the filing system, and the methods used to store and retrieve files on a storage medium are detailed in MS-DOS.TM. Programmer's Reference (Microsoft.TM. Press, 1992).
On the other hand, the filing system used by Apple.TM. Macintosh.TM. computers encodes onto a storage medium a "hierarchical filing system" (HFS) detailed by U.S. Pat. No. 4,945,475 and described further in Inside Macintosh.TM.: Files (Addison Wesley, 1993).
The differences between the methods of these two operating or filing systems result in physical differences in the data structures used to track critical information and the locations of these data structures on the storage medium.
A user wishing to purchase an empty storage medium such as a floppy disk may purchase it in a state which requires it to undergo a process on a computer system known as "initialization" or "formatting." This involves a process performed by the user's computer where the data structures needed by the target operating system, whether it be DOS or Macintosh.TM., are written to the storage medium. Once these data structures are written, the medium can then be used to store and subsequently retrieve files.
Alternatively, a user may obtain a storage medium which has already undergone this process for a specific operating system. For example, preinitialized media are currently available in either DOS or Macintosh.TM. format. As such, a user who wishes to obtain a preinitialized storage medium must seek out and choose the product which matches the operating system required, whether DOS or Macintosh.
There is a need for a method of creating a preinitialized storage medium which may be used to store files and directories on either DOS or Macintosh.TM. computers. Such a medium would not require the user to perform an initialization process. Also, such a medium could be provided to users of either DOS or Macintosh operating systems, freeing a user from the need to locate a medium specifically preinitialized for one specific operating system.